JPS56126788A - Power supply circuit for timepiece - Google Patents

Abstract

PURPOSE:To make possible the automatic starting of a voltage depression system for clock circuit by starting an electric charge transfer-type voltage depression circuit through the feeding of a power supply for a low voltage system for a prearranged period through the intermediary of a switching circuit after detecting a depression of voltage. CONSTITUTION:An electric charge transfer-type voltage depression circuit 3 which is controlled by a frequency dividing circuit 2 is not started because of the nonstarting of an oscillator 1 right after the replacement of a battery 4. A depression of voltage under this condition is detected by means of an inverter 6 and FF7 and a switching circuit 5 is switched over at an output from FF7. Following this process, a voltage for a low voltage system from a battery 4 is applied to a clock circuit for the oscillator 1, etc. through the intermediary of the circuit 2, starting the circuit 3. In the meantime, a timer 8, complying to a frequency dividing output of 1Hz which is output from the circuit 2, resets FF7 after the elapse of a prearranged timer time and the clock circuit is normally driven at a depressed voltage through the circuits 3, 5. Under this constitution, it is possible to automatically restart the voltage depression circuit without manual operation at time of battery replacement or at time of temporary oscillator stop.